I find myself often using (modified) examples to test in IE and it's a pain to have to add the shims in every time. Might as well just add them in always.
The initial thought was that an opacity animation from 0.01 to 1 causes trouble on some browser. But after testing on opera 12.15, ff 23, ie 10, chrome 30, desktop/mobile safari 7 and chrome android I confirm this works.